The present invention relates to drill bit grinding machines, and relates more particularly to such a drill bit grinding machine which automatically grinds the stationary point and lip of the spur of the drill bit.
A drill bit is generally comprised of a shaft, a twist defining a spur, and a tip. The tip comprises two lips, two flanks, and a stationary point at the intersected end of the lips. The stationary point must be axially in perfect alignment with the axial axis of the drill bit so that the drill bit can be positively and accurately drilled into the workpiece. Because the stationary point of the drill bit wears quickly with use, the stationary point and the lips of the flank must be regularly ground. However, according to conventional grinding machines, the grinding of the stationary point and the grinding of the flanks of drill bit cannot be simultaneously completed, i.e., a secondary grinding process is needed to grind the flanks after the grinding of the stationary point. While grinding, the operator must use angle measuring means to measure the angle of the tip. This complicated grinding procedure greatly increases the grinding cost, and the grinding quality is difficult to be well controlled.